Improvement in balance-spring holders for watches



J. SHAW.

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WITNESSES INVENTOR 44m/m a 2 Man/ %0%pf6i0 wwwwva ATTORN EYS.

UNITED STATES PATENT OFFICE.

. JACOB SHAW, or SHELBY, onro.

IMPROVEMENT IN BALANCE-SPRING HOLDERS FOR WATCHES.

Specification forming part of Letters Patent No. 149,795, dated April 14 1874 :application filed June 23, 1873.

To all whom it may concern:

7 Be it known that I, J A0013 SHAW, of Shelby, Itichland county, Ohio, have invented an Improvement in Attaching Hair or Balance Springs to atches, of which the following is a specification:

This invention relates to a new and in1- proved mode of securing the outer ends of the balance or hair springs of timepieces, whereby these springs are firmly held in a plane parallel to the plane of their balance-wheels, as will be hereinafter explained.

Prior to my invention and improvement hair-springs in watches have been held by devices which clamp their sides, thus rendering the position of these springs with respect to the balance-wheels very uncertain.

My object is to obtain a device by means of which the springs can be readily and properly adjusted and confined in place.

In the annexed drawings, A designates the plate of a watch or chronometer, to which a bed-plate or bracket, 13, is firmly secured by means of a screw, a, and steadying pin a. The overhanging portion of this bracket is rectangular, and in that portion which is designated by the letter I) I form a curved groove, 0, for receiving the lower edge of a hair-sprin g, S, as shown in Fi g. 3. The curve of the groove 0 maybe concentric to the axis of the balance wheel, and it may be an are which is onei'ourth, more or less,the diameter of the sprin O designates a spring clamp, which corresponds in its shape to the shape of the bracket 13, and which is secured to this bracket by means of the screw a and steady-pin a. The

portion lettered b of this clamp is parallel, or nearly so, to the portion of the bracket B let- 'tered b. It is between these two portions b b that the spring S is confinedby its edges, they serving as clampingjaws. hen the spring S is clamped as described, it is steadied by means of the groove 0 and two pins, 1) p, which latter rise perpendicularly from the portion b, and pass through the upper clamping portion 1). For the purpose of readily applying the spring S between the portions 1) b, and removing it therefrom, I employ a wedge, 10, which is applied as shown in Figs. 1 and 3. Byforcin g this wedge in between the parts B and O the jaw b will be raised so as to free the spring S, or allow it to be adjusted in its groove 0. I am thus able to remove or apply the spring without detaching the spring C.

It is obvious from the above description that if the bottom of the groove 0 is in a plane parallel to the plane of the balance-wheel of the time-piece the spring S will be confined in a proper position, and thus positively held.

Having described my invention, what I claim as new, and desire to secure by Letters Pat out, is-

1. The spring-clam 'i 0, combined with the portion 1) of the base or bracket B, grooved to receive the spring S, substantially as described.

2. The wedge 10, applied between the springclamp G and the grooved bracket B, as and for the purposes described.

3. The steady pins 12 1), combined with the spring-clamp O and the groove 0 in the bracket B, as and for the purposes set forth.

JACOB SHAW.

Witnesses:

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